VARIABLE-BEAM LIGHT SOURCE AND RELATED METHODS

• US 20140084809A1
• Filed: 09/24/2013
• Published: 03/27/2014
• Est. Priority Date: 09/24/2012
• Status: Abandoned Application

• Current Assignee: LEDVANCE LLC (MLS Co. Ltd.)
• Original Assignee: LEDVANCE LLC (MLS Co. Ltd.)
• Inventors: Catalano, Anthony W.
• Application Number:
  US14/035,027
• Publication Number:
  US 20140084809A1
• Time in Patent Office: Days
• US Class Current: 315/292
• CPC Class Codes: F21V 14/00 Controlling the distribution of the light emitted by adjustment of elements reflectors with provision for adjusting the curvature F21V7/16; light filters or the like with provision for controlling the colour or intensity F21V9/40; screens using adjustable parallel laminae or strips F21V11/04; screens using iris-type diaphragms F21V11/10; screens using movable sheets without apertures F21V11/18; adjustable mountings for lighting devices F21V21/14
• CPC Class Codes: F21V 23/003 the elements being electronics drivers or controllers for operating the light source, e.g. for a LED array
• CPC Class Codes: F21V 23/04 the elements being switches safety devices F21V25/00
• CPC Class Codes: F21V 7/045 with spherical surface
• CPC Class Codes: F21V 7/048 with facets structure
• CPC Class Codes: F21V 7/06 with parabolic curvature
• CPC Class Codes: F21Y 2105/10 comprising a two-dimensional array of point-like light-generating elements
• CPC Class Codes: F21Y 2105/12 characterised by the geometrical disposition of the light-generating elements, e.g. arranging light-generating elements in differing patterns or densities
• CPC Class Codes: F21Y 2115/10 Light-emitting diodes [LED]
• CPC Class Codes: H05B 45/10 Controlling the intensity of the light

Abstract

Light sources with arrangements of multiple LEDs (or other light-emitting devices) disposed at or near the focus of a reflecting optic and controllable individually or in groups facilitate varying the angular distribution of the light beam (e.g., the beam divergence) via the drive currents supplied to the LEDs.

Claims

1. A light source producing a beam of variable divergence, comprising:

(a) a concave reflecting optic;

(b) an arrangement of light-emitting devices disposed fixedly relative to and oriented to face in the same direction as the reflecting optic, light emitted by the light-emitting devices and reflected by the optic forming a light beam; and

(c) driver circuitry for controlling drive currents to the light-emitting devices individually or in groups thereof to thereby variably control a divergence of the light beam.

2. The light source of claim 1, wherein the arrangement of light-emitting devices is disposed substantially at a focus of the reflecting optic.

3. The light source of claim 1, wherein the light-emitting devices comprise LEDs.

4. The light source of claim 1, wherein the reflecting optic is at least one of faceted or textured.

5. The light source of claim 1, wherein the reflecting optic comprises a parabolic reflector.

6. The light source of claim 5, wherein the arrangement of light-emitting devices is disposed substantially at a focal plane of the parabolic reflector.

7. The light source of claim 1, wherein a diameter of the reflecting optic is greater than a largest dimension of the arrangement of light-emitting devices.

8. The light source of claim 7, wherein the diameter of the reflecting optic is at least twice as large as the largest dimension of the arrangement of light-emitting devices.

9. The light source of claim 1, wherein a largest dimension of the arrangement of light-emitting devices is greater than a focal length of the reflecting optic.

10. The light source of claim 9, wherein the largest dimension of the arrangement of light-emitting devices is at least twice as large as the focal length of the reflecting optic.

11. The light source of claim 1, wherein the circuitry is configured to control the drive currents to the light-emitting devices based on their distance from a center of the arrangement.

12. The light source of claim 11, wherein the circuitry is configured to narrow the beam by providing non-zero drive currents only to light-emitting devices within a specified distance from the center.

13. The light source of claim 1, wherein the circuitry is configured to further uniformly vary the drive currents to all light-emitting devices to thereby vary the intensity of the beam.

14. The light source of claim 1, wherein the circuitry is configured to selectively drive a subset of the light-emitting devices so as to generate a pattern.

15. The light source of claim 1, wherein the circuitry is programmable.

16. The light source of claim 1, wherein the circuitry is configured to control the drive currents based on at least one of sizes or positions of respective light-emitting devices.

17. The light source of claim 1, wherein a light-emitting device located at a center of the arrangement is a higher-power device than a light-emitting device located at a periphery of the arrangement.

18. The light source of claim 1, wherein the arrangement of the light-emitting devices is planar.

19. A method of varying divergence of a light source comprising a concave reflecting optic and, disposed fixedly relative to and oriented to face in the same direction as the reflecting optic, an arrangement of light-emitting devices controllably individually or in groups, the method comprising:

driving the light-emitting devices so as to create a light beam emerging from the focusing optic; and

controlling the drive currents to the light-emitting devices, individually or in groups thereof, based, at least in part, on the distance of the devices from a center of the arrangement so that the beam has a divergence variably determined by the controlled drive currents.

20. The method of claim 19, wherein the light-emitting devices comprise LEDs.

21. The method of claim 19, wherein the reflecting optic comprises a parabolic reflector.

22. The method of claim 19, wherein controlling the drive currents comprises decreasing the drive currents to LEDs in an outer region of the arrangement to thereby narrow the beam.

23. The method of claim 19, further comprising simultaneously and uniformly varying the drive currents to all LEDs to thereby vary the beam brightness.

24. The method of claim 19, further comprising programming driver circuitry controlling the drive currents.